I suspect it's not quite that simple. First, is there actually enough demand for ad-free TVs to make the option worth including? I personally probably wouldn't pay $20 to avoid ads in the home screen since those kind of ads are just a minor nuisance, which makes me question the size of the market for the ad-free option.
Second, what would the pricing be for the option?
If it's $10-20, that'd probably be fine, similar to what Amazon did for Kindle. But if it's more than that, then I bet the negative PR they would get for including the option outweighs the potential benefit to customers. "I would never buy an X, they're extremely greedy and want $50 just not to show ads. Crazy. I'll buy Y brand instead (which has ads but no 'corporate greed' option to not show them)".
They do actually sell screens with no ads for businesses, as mentioned. They just seemingly won't put them in stores where consumers can purchase them easily.
I would look at Google Contributor and similar efforts as a supporting argument. They tried a few times to allow you to pay directly and not see ads, and each time failed reportedly because it was a not loss for publishers. Google is not unbiased here but I suspect that this was a real problem and that it’d be even worse on TVs since most people are used to disruptive ads there.
Second, what would the pricing be for the option?
If it's $10-20, that'd probably be fine, similar to what Amazon did for Kindle. But if it's more than that, then I bet the negative PR they would get for including the option outweighs the potential benefit to customers. "I would never buy an X, they're extremely greedy and want $50 just not to show ads. Crazy. I'll buy Y brand instead (which has ads but no 'corporate greed' option to not show them)".